Field of the Invention
The present invention relates to a printer.
Description of the Related Art
As a printer, there is conventionally known a line-type jetting head including head chips arranged in a width direction of a recording medium. In such a jetting head, two head chips are adjacent to each other in the width direction of the recording medium and deviate from each other in a conveyance direction of the recording medium. Further, ends of the two head chips are arrayed in the conveyance direction of the recording medium.
In an area, of the jetting head, in which the two adjacent head chips face each other in the conveyance direction, nozzles of the two head chips are used selectively in a predefined boundary position. In that case, if the two head chips differ in jetting characteristics, landing deviations of ink jetted from the two head chips occur, resulting in streak-like density unevenness.
As a means of solving the above problem, there is conventionally known a printer in which an area where two head chips face each other in a conveyance direction is divided into a section for jetting ink from only one of the two head chips, a section for jetting ink from only the other of the two head chips, and a section for jetting ink from both of the two head chips. In the following, for easy explanation, each nozzle which is arranged at a boundary of the section where both of the two head chips are used in the area where the two head chips face each other in the conveyance direction is referred to as a “boundary nozzle”. In an area for which printing is performed with the boundary nozzles, droplets of ink jetted from nozzles of the respective two head chips land in a dispersed or scattered state. This prevents density unevenness which would be otherwise caused by the difference in jetting characteristics of nozzles between the respective two head chips.
Another publicly known printer has a jetting head in which four head chips are arranged zigzag, wherein each roller pressing a recording medium during printing is provided between the head chips. Namely, each roller is arranged at a position next to one of two adjacent head chips in a width direction of the recording medium and facing the other of the two adjacent head chips in a conveyance direction of the recording medium.